3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2018, Intel Corporation.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/slab.h>
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/fcntl.h>
25 #include <linux/poll.h>
26 #include <linux/init.h>
27 #include <linux/ioctl.h>
28 #include <linux/cdev.h>
29 #include <linux/sched/signal.h>
30 #include <linux/uuid.h>
31 #include <linux/compat.h>
32 #include <linux/jiffies.h>
33 #include <linux/interrupt.h>
35 #include <linux/mei.h>
41 * mei_open - the open function
43 * @inode: pointer to inode structure
44 * @file: pointer to file structure
46 * Return: 0 on success, <0 on error
48 static int mei_open(struct inode *inode, struct file *file)
50 struct mei_device *dev;
55 dev = container_of(inode->i_cdev, struct mei_device, cdev);
59 mutex_lock(&dev->device_lock);
61 if (dev->dev_state != MEI_DEV_ENABLED) {
62 dev_dbg(dev->dev, "dev_state != MEI_ENABLED dev_state = %s\n",
63 mei_dev_state_str(dev->dev_state));
68 cl = mei_cl_alloc_linked(dev);
75 file->private_data = cl;
77 mutex_unlock(&dev->device_lock);
79 return nonseekable_open(inode, file);
82 mutex_unlock(&dev->device_lock);
87 * mei_release - the release function
89 * @inode: pointer to inode structure
90 * @file: pointer to file structure
92 * Return: 0 on success, <0 on error
94 static int mei_release(struct inode *inode, struct file *file)
96 struct mei_cl *cl = file->private_data;
97 struct mei_device *dev;
100 if (WARN_ON(!cl || !cl->dev))
105 mutex_lock(&dev->device_lock);
107 rets = mei_cl_disconnect(cl);
109 mei_cl_flush_queues(cl, file);
110 cl_dbg(dev, cl, "removing\n");
114 file->private_data = NULL;
118 mutex_unlock(&dev->device_lock);
124 * mei_read - the read function.
126 * @file: pointer to file structure
127 * @ubuf: pointer to user buffer
128 * @length: buffer length
129 * @offset: data offset in buffer
131 * Return: >=0 data length on success , <0 on error
133 static ssize_t mei_read(struct file *file, char __user *ubuf,
134 size_t length, loff_t *offset)
136 struct mei_cl *cl = file->private_data;
137 struct mei_device *dev;
138 struct mei_cl_cb *cb = NULL;
139 bool nonblock = !!(file->f_flags & O_NONBLOCK);
142 if (WARN_ON(!cl || !cl->dev))
148 mutex_lock(&dev->device_lock);
149 if (dev->dev_state != MEI_DEV_ENABLED) {
164 cb = mei_cl_read_cb(cl, file);
171 rets = mei_cl_read_start(cl, length, file);
172 if (rets && rets != -EBUSY) {
173 cl_dbg(dev, cl, "mei start read failure status = %zd\n", rets);
182 mutex_unlock(&dev->device_lock);
183 if (wait_event_interruptible(cl->rx_wait,
184 !list_empty(&cl->rd_completed) ||
185 !mei_cl_is_connected(cl))) {
186 if (signal_pending(current))
190 mutex_lock(&dev->device_lock);
192 if (!mei_cl_is_connected(cl)) {
197 cb = mei_cl_read_cb(cl, file);
204 /* now copy the data to user space */
207 cl_dbg(dev, cl, "read operation failed %zd\n", rets);
211 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
212 cb->buf.size, cb->buf_idx, *offset);
213 if (*offset >= cb->buf_idx) {
218 /* length is being truncated to PAGE_SIZE,
219 * however buf_idx may point beyond that */
220 length = min_t(size_t, length, cb->buf_idx - *offset);
222 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
223 dev_dbg(dev->dev, "failed to copy data to userland\n");
230 /* not all data was read, keep the cb */
231 if (*offset < cb->buf_idx)
239 cl_dbg(dev, cl, "end mei read rets = %zd\n", rets);
240 mutex_unlock(&dev->device_lock);
244 * mei_write - the write function.
246 * @file: pointer to file structure
247 * @ubuf: pointer to user buffer
248 * @length: buffer length
249 * @offset: data offset in buffer
251 * Return: >=0 data length on success , <0 on error
253 static ssize_t mei_write(struct file *file, const char __user *ubuf,
254 size_t length, loff_t *offset)
256 struct mei_cl *cl = file->private_data;
257 struct mei_cl_cb *cb;
258 struct mei_device *dev;
261 if (WARN_ON(!cl || !cl->dev))
266 mutex_lock(&dev->device_lock);
268 if (dev->dev_state != MEI_DEV_ENABLED) {
273 if (!mei_cl_is_connected(cl)) {
274 cl_err(dev, cl, "is not connected");
279 if (!mei_me_cl_is_active(cl->me_cl)) {
284 if (length > mei_cl_mtu(cl)) {
294 while (cl->tx_cb_queued >= dev->tx_queue_limit) {
295 if (file->f_flags & O_NONBLOCK) {
299 mutex_unlock(&dev->device_lock);
300 rets = wait_event_interruptible(cl->tx_wait,
301 cl->writing_state == MEI_WRITE_COMPLETE ||
302 (!mei_cl_is_connected(cl)));
303 mutex_lock(&dev->device_lock);
305 if (signal_pending(current))
309 if (!mei_cl_is_connected(cl)) {
315 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
321 rets = copy_from_user(cb->buf.data, ubuf, length);
323 dev_dbg(dev->dev, "failed to copy data from userland\n");
329 rets = mei_cl_write(cl, cb);
331 mutex_unlock(&dev->device_lock);
336 * mei_ioctl_connect_client - the connect to fw client IOCTL function
338 * @file: private data of the file object
339 * @data: IOCTL connect data, input and output parameters
341 * Locking: called under "dev->device_lock" lock
343 * Return: 0 on success, <0 on failure.
345 static int mei_ioctl_connect_client(struct file *file,
346 struct mei_connect_client_data *data)
348 struct mei_device *dev;
349 struct mei_client *client;
350 struct mei_me_client *me_cl;
354 cl = file->private_data;
357 if (dev->dev_state != MEI_DEV_ENABLED)
360 if (cl->state != MEI_FILE_INITIALIZING &&
361 cl->state != MEI_FILE_DISCONNECTED)
364 /* find ME client we're trying to connect to */
365 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
367 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
368 &data->in_client_uuid);
373 if (me_cl->props.fixed_address) {
374 bool forbidden = dev->override_fixed_address ?
375 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
377 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
378 &data->in_client_uuid);
384 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
386 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
387 me_cl->props.protocol_version);
388 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
389 me_cl->props.max_msg_length);
391 /* prepare the output buffer */
392 client = &data->out_client_properties;
393 client->max_msg_length = me_cl->props.max_msg_length;
394 client->protocol_version = me_cl->props.protocol_version;
395 dev_dbg(dev->dev, "Can connect?\n");
397 rets = mei_cl_connect(cl, me_cl, file);
400 mei_me_cl_put(me_cl);
405 * mei_ioctl_client_notify_request -
406 * propagate event notification request to client
408 * @file: pointer to file structure
409 * @request: 0 - disable, 1 - enable
411 * Return: 0 on success , <0 on error
413 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
415 struct mei_cl *cl = file->private_data;
417 if (request != MEI_HBM_NOTIFICATION_START &&
418 request != MEI_HBM_NOTIFICATION_STOP)
421 return mei_cl_notify_request(cl, file, (u8)request);
425 * mei_ioctl_client_notify_get - wait for notification request
427 * @file: pointer to file structure
428 * @notify_get: 0 - disable, 1 - enable
430 * Return: 0 on success , <0 on error
432 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
434 struct mei_cl *cl = file->private_data;
436 bool block = (file->f_flags & O_NONBLOCK) == 0;
439 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
443 *notify_get = notify_ev ? 1 : 0;
448 * mei_ioctl - the IOCTL function
450 * @file: pointer to file structure
451 * @cmd: ioctl command
452 * @data: pointer to mei message structure
454 * Return: 0 on success , <0 on error
456 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
458 struct mei_device *dev;
459 struct mei_cl *cl = file->private_data;
460 struct mei_connect_client_data connect_data;
461 u32 notify_get, notify_req;
465 if (WARN_ON(!cl || !cl->dev))
470 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
472 mutex_lock(&dev->device_lock);
473 if (dev->dev_state != MEI_DEV_ENABLED) {
479 case IOCTL_MEI_CONNECT_CLIENT:
480 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
481 if (copy_from_user(&connect_data, (char __user *)data,
482 sizeof(struct mei_connect_client_data))) {
483 dev_dbg(dev->dev, "failed to copy data from userland\n");
488 rets = mei_ioctl_connect_client(file, &connect_data);
492 /* if all is ok, copying the data back to user. */
493 if (copy_to_user((char __user *)data, &connect_data,
494 sizeof(struct mei_connect_client_data))) {
495 dev_dbg(dev->dev, "failed to copy data to userland\n");
502 case IOCTL_MEI_NOTIFY_SET:
503 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
504 if (copy_from_user(¬ify_req,
505 (char __user *)data, sizeof(notify_req))) {
506 dev_dbg(dev->dev, "failed to copy data from userland\n");
510 rets = mei_ioctl_client_notify_request(file, notify_req);
513 case IOCTL_MEI_NOTIFY_GET:
514 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
515 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
519 dev_dbg(dev->dev, "copy connect data to user\n");
520 if (copy_to_user((char __user *)data,
521 ¬ify_get, sizeof(notify_get))) {
522 dev_dbg(dev->dev, "failed to copy data to userland\n");
534 mutex_unlock(&dev->device_lock);
539 * mei_compat_ioctl - the compat IOCTL function
541 * @file: pointer to file structure
542 * @cmd: ioctl command
543 * @data: pointer to mei message structure
545 * Return: 0 on success , <0 on error
548 static long mei_compat_ioctl(struct file *file,
549 unsigned int cmd, unsigned long data)
551 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
557 * mei_poll - the poll function
559 * @file: pointer to file structure
560 * @wait: pointer to poll_table structure
564 static __poll_t mei_poll(struct file *file, poll_table *wait)
566 __poll_t req_events = poll_requested_events(wait);
567 struct mei_cl *cl = file->private_data;
568 struct mei_device *dev;
572 if (WARN_ON(!cl || !cl->dev))
577 mutex_lock(&dev->device_lock);
579 notify_en = cl->notify_en && (req_events & EPOLLPRI);
581 if (dev->dev_state != MEI_DEV_ENABLED ||
582 !mei_cl_is_connected(cl)) {
588 poll_wait(file, &cl->ev_wait, wait);
593 if (req_events & (EPOLLIN | EPOLLRDNORM)) {
594 poll_wait(file, &cl->rx_wait, wait);
596 if (!list_empty(&cl->rd_completed))
597 mask |= EPOLLIN | EPOLLRDNORM;
599 mei_cl_read_start(cl, mei_cl_mtu(cl), file);
602 if (req_events & (EPOLLOUT | EPOLLWRNORM)) {
603 poll_wait(file, &cl->tx_wait, wait);
604 if (cl->tx_cb_queued < dev->tx_queue_limit)
605 mask |= EPOLLOUT | EPOLLWRNORM;
609 mutex_unlock(&dev->device_lock);
614 * mei_cl_is_write_queued - check if the client has pending writes.
616 * @cl: writing host client
618 * Return: true if client is writing, false otherwise.
620 static bool mei_cl_is_write_queued(struct mei_cl *cl)
622 struct mei_device *dev = cl->dev;
623 struct mei_cl_cb *cb;
625 list_for_each_entry(cb, &dev->write_list, list)
628 list_for_each_entry(cb, &dev->write_waiting_list, list)
635 * mei_fsync - the fsync handler
637 * @fp: pointer to file structure
642 * Return: 0 on success, -ENODEV if client is not connected
644 static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
646 struct mei_cl *cl = fp->private_data;
647 struct mei_device *dev;
650 if (WARN_ON(!cl || !cl->dev))
655 mutex_lock(&dev->device_lock);
657 if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
662 while (mei_cl_is_write_queued(cl)) {
663 mutex_unlock(&dev->device_lock);
664 rets = wait_event_interruptible(cl->tx_wait,
665 cl->writing_state == MEI_WRITE_COMPLETE ||
666 !mei_cl_is_connected(cl));
667 mutex_lock(&dev->device_lock);
669 if (signal_pending(current))
673 if (!mei_cl_is_connected(cl)) {
680 mutex_unlock(&dev->device_lock);
685 * mei_fasync - asynchronous io support
687 * @fd: file descriptor
688 * @file: pointer to file structure
691 * Return: negative on error,
692 * 0 if it did no changes,
693 * and positive a process was added or deleted
695 static int mei_fasync(int fd, struct file *file, int band)
698 struct mei_cl *cl = file->private_data;
700 if (!mei_cl_is_connected(cl))
703 return fasync_helper(fd, file, band, &cl->ev_async);
707 * fw_status_show - mei device fw_status attribute show method
709 * @device: device pointer
710 * @attr: attribute pointer
711 * @buf: char out buffer
713 * Return: number of the bytes printed into buf or error
715 static ssize_t fw_status_show(struct device *device,
716 struct device_attribute *attr, char *buf)
718 struct mei_device *dev = dev_get_drvdata(device);
719 struct mei_fw_status fw_status;
723 mutex_lock(&dev->device_lock);
724 err = mei_fw_status(dev, &fw_status);
725 mutex_unlock(&dev->device_lock);
727 dev_err(device, "read fw_status error = %d\n", err);
731 for (i = 0; i < fw_status.count; i++)
732 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
733 fw_status.status[i]);
736 static DEVICE_ATTR_RO(fw_status);
739 * hbm_ver_show - display HBM protocol version negotiated with FW
741 * @device: device pointer
742 * @attr: attribute pointer
743 * @buf: char out buffer
745 * Return: number of the bytes printed into buf or error
747 static ssize_t hbm_ver_show(struct device *device,
748 struct device_attribute *attr, char *buf)
750 struct mei_device *dev = dev_get_drvdata(device);
751 struct hbm_version ver;
753 mutex_lock(&dev->device_lock);
755 mutex_unlock(&dev->device_lock);
757 return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
759 static DEVICE_ATTR_RO(hbm_ver);
762 * hbm_ver_drv_show - display HBM protocol version advertised by driver
764 * @device: device pointer
765 * @attr: attribute pointer
766 * @buf: char out buffer
768 * Return: number of the bytes printed into buf or error
770 static ssize_t hbm_ver_drv_show(struct device *device,
771 struct device_attribute *attr, char *buf)
773 return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
775 static DEVICE_ATTR_RO(hbm_ver_drv);
777 static ssize_t tx_queue_limit_show(struct device *device,
778 struct device_attribute *attr, char *buf)
780 struct mei_device *dev = dev_get_drvdata(device);
783 mutex_lock(&dev->device_lock);
784 size = dev->tx_queue_limit;
785 mutex_unlock(&dev->device_lock);
787 return snprintf(buf, PAGE_SIZE, "%u\n", size);
790 static ssize_t tx_queue_limit_store(struct device *device,
791 struct device_attribute *attr,
792 const char *buf, size_t count)
794 struct mei_device *dev = dev_get_drvdata(device);
799 err = kstrtouint(buf, 10, &inp);
802 if (inp > MEI_TX_QUEUE_LIMIT_MAX || inp < MEI_TX_QUEUE_LIMIT_MIN)
806 mutex_lock(&dev->device_lock);
807 dev->tx_queue_limit = limit;
808 mutex_unlock(&dev->device_lock);
812 static DEVICE_ATTR_RW(tx_queue_limit);
815 * fw_ver_show - display ME FW version
817 * @device: device pointer
818 * @attr: attribute pointer
819 * @buf: char out buffer
821 * Return: number of the bytes printed into buf or error
823 static ssize_t fw_ver_show(struct device *device,
824 struct device_attribute *attr, char *buf)
826 struct mei_device *dev = dev_get_drvdata(device);
827 struct mei_fw_version *ver;
833 for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++)
834 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%u:%u.%u.%u.%u\n",
835 ver[i].platform, ver[i].major, ver[i].minor,
836 ver[i].hotfix, ver[i].buildno);
839 static DEVICE_ATTR_RO(fw_ver);
841 static struct attribute *mei_attrs[] = {
842 &dev_attr_fw_status.attr,
843 &dev_attr_hbm_ver.attr,
844 &dev_attr_hbm_ver_drv.attr,
845 &dev_attr_tx_queue_limit.attr,
846 &dev_attr_fw_ver.attr,
849 ATTRIBUTE_GROUPS(mei);
852 * file operations structure will be used for mei char device.
854 static const struct file_operations mei_fops = {
855 .owner = THIS_MODULE,
857 .unlocked_ioctl = mei_ioctl,
859 .compat_ioctl = mei_compat_ioctl,
862 .release = mei_release,
866 .fasync = mei_fasync,
870 static struct class *mei_class;
871 static dev_t mei_devt;
872 #define MEI_MAX_DEVS MINORMASK
873 static DEFINE_MUTEX(mei_minor_lock);
874 static DEFINE_IDR(mei_idr);
877 * mei_minor_get - obtain next free device minor number
879 * @dev: device pointer
881 * Return: allocated minor, or -ENOSPC if no free minor left
883 static int mei_minor_get(struct mei_device *dev)
887 mutex_lock(&mei_minor_lock);
888 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
891 else if (ret == -ENOSPC)
892 dev_err(dev->dev, "too many mei devices\n");
894 mutex_unlock(&mei_minor_lock);
899 * mei_minor_free - mark device minor number as free
901 * @dev: device pointer
903 static void mei_minor_free(struct mei_device *dev)
905 mutex_lock(&mei_minor_lock);
906 idr_remove(&mei_idr, dev->minor);
907 mutex_unlock(&mei_minor_lock);
910 int mei_register(struct mei_device *dev, struct device *parent)
912 struct device *clsdev; /* class device */
915 ret = mei_minor_get(dev);
919 /* Fill in the data structures */
920 devno = MKDEV(MAJOR(mei_devt), dev->minor);
921 cdev_init(&dev->cdev, &mei_fops);
922 dev->cdev.owner = parent->driver->owner;
925 ret = cdev_add(&dev->cdev, devno, 1);
927 dev_err(parent, "unable to add device %d:%d\n",
928 MAJOR(mei_devt), dev->minor);
932 clsdev = device_create_with_groups(mei_class, parent, devno,
934 "mei%d", dev->minor);
936 if (IS_ERR(clsdev)) {
937 dev_err(parent, "unable to create device %d:%d\n",
938 MAJOR(mei_devt), dev->minor);
939 ret = PTR_ERR(clsdev);
943 ret = mei_dbgfs_register(dev, dev_name(clsdev));
945 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
952 device_destroy(mei_class, devno);
954 cdev_del(&dev->cdev);
959 EXPORT_SYMBOL_GPL(mei_register);
961 void mei_deregister(struct mei_device *dev)
965 devno = dev->cdev.dev;
966 cdev_del(&dev->cdev);
968 mei_dbgfs_deregister(dev);
970 device_destroy(mei_class, devno);
974 EXPORT_SYMBOL_GPL(mei_deregister);
976 static int __init mei_init(void)
980 mei_class = class_create(THIS_MODULE, "mei");
981 if (IS_ERR(mei_class)) {
982 pr_err("couldn't create class\n");
983 ret = PTR_ERR(mei_class);
987 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
989 pr_err("unable to allocate char dev region\n");
993 ret = mei_cl_bus_init();
995 pr_err("unable to initialize bus\n");
1002 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1004 class_destroy(mei_class);
1009 static void __exit mei_exit(void)
1011 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1012 class_destroy(mei_class);
1016 module_init(mei_init);
1017 module_exit(mei_exit);
1019 MODULE_AUTHOR("Intel Corporation");
1020 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
1021 MODULE_LICENSE("GPL v2");